Henry Thomas Joynt Thacker (20 March 1870 – 3 May 1939) was a medical doctor, New Zealand Member of Parliament and Mayor of Christchurch.

He represented Canterbury in rugby union in 1889 and 1891 and assisted in the development of Richard Arnst.

Thacker was the first president of the Canterbury Rugby Football League when the organisation began holding competitions in 1913.

[7][8] Thacker contested the 1908 and 1911 general elections without success in the Lyttelton and Christchurch East electorates, respectively.

[4][9] He then contested the Lyttelton by-election in 1913 as an independent Liberal, coming fourth with 5% of the vote in the first ballot.